On December 23, the Houthis media wing released a video showing the moment when the Houthis shot down a CH-4B unmanned combat aerial vehicle (UCAV) of the Saudi Air Force over the northern Yemeni provinceo of Saada.

Saudi Arabia had bought several CH-4B UCAVs from China. The Saudi Air Force has been actively employing these UCAVs in the Yemeni conflict.

https://southfront.org/video-houthis-shoot-down-saudi-arabias-ch-4b-combat-uav-over-saada-province/